Nucky is rocked by an insurrection among his inner circle; Chalky's life and livelihood are threatened by a vicious KKK attack; Margaret copes with her son's disciplinary problems; Angela vies with Gillian for Jimmy's affections at home; Van Alden shows his wife Rose around town as an anniversary present. Written by HBO Publicity...

Valentines Day starts abruptly for Margaret when she wakes to news of Nucky's arrest for election fraud. While government agents are busy searching for evidence in Nucky's office, Margaret makes a bold choice to help him by disguising herself.

In New York, Jimmy decides to expand his business visiting an old adversary Arnold Rothstein for a proposition. Unfortunately for Darmondy, Rothstein decides to pass but Charlie Luciano and Meyer Lansky wait in the wings to pitch their own business proposal for Jimmy over some poker...

At a birthday party for Mayor Bader, Nucky's attorney has a legal brainstorm that could turn the tide in Nuck's election-rigging case. Facing a local liquor surplus, Jimmy and Mickey head to Philadelphia in search of buyers, while Nucky strikes an unlikely deal to get booze into Atlantic City. Eli frets over the Commodore's ability to lead; Margaret doles out staff bonuses; Chalky is cornered at work and at home; Owen puts his munitions expertise to work; Van Alden's agents target Mickey's warehouse; Richard lets down his guard in the name of art; Gillian recalls her "first time" with the Commodore...

On Memorial Day Nucky Thompson and Jimmy Darmody both give successful speeches. After, Jimmy and Eli Thompson meet with the memorial committee, who are The Commodore's financial backers in the coup against Nucky. The committee have lost faith in the plan and are concerned by The Commodore's absence. Jimmy is unable to reassure them, then Jackson Parkhurst strikes Jimmy with his cane, bringing the meeting to an abrupt end.

Nucky gets the favor he wanted from Attorney General Harry Daugherty — assistance with his legal troubles. In return he will repay Daugherty with a day's entertainment. Eli visits Nucky at home, desperate to back out of the coup. Nucky refuses to help him, they get into a brutal fight which is broken up by Margaret Schroeder holding a shotgun to Eli's head...

Margaret Schroeder prepares her son for first communion necessitating a confession of her own to set an example. She admits impure thoughts for Owen Sleater but says nothing of her arrangement with Nucky Thompson. Nucky's election fraud troubles return when a senator pressures the Attorney General to pursue a conviction. At the hospital Nelson Van Alden teeters on the brink of professional and personal confessions as his suspicious subordinate slowly succumbs to third degree burns. Lucy Danziger gives birth alone. Jimmy Darmody is surprised when Lucky Luciano is protecting the liquor shipment he goes to hijack; instead of completing the hijacking Jimmy decides to follow advice from a new source and partners with Luciano to take over Nucky's entire bootlegging operation...

Nelson Van Alden is unable to pay Lucy Danziger for the custody of their baby as they agreed. He is also put out when a new prosecutor, Esther Randolph, takes over his office to work on the election rigging case against Nucky Thompson. Lucy goes to Nucky for help with the baby, she explains that Van Alden is the father and Nucky gives her money. Nucky uses the information in an attempt to blackmail Van Alden into spying on Rudolph. Lucy leaves the baby with Van Alden and he bonds with her. Van Alden goes to Rudolph and gives her his investigative file on Nucky.

Nucky Thompson has problems on multiple fronts. Since his brush with death he is having strange dreams and getting little sleep. Margaret Schroeder is worried about her sick daughter and the safety of Nucky and her family after the shooting. Esther Randolph continues to build the legal case against him. He confirms that Jimmy Darmody is behind the assassination attempt. Finally his father, Ethan Thompson, dies. Nucky takes advice from Johnny Torrio and Arnold Rothstein and decides to feign retirement and go to Ireland to raise funds for a counterattack. He asks Chalky White to orchestrate a strike by African American workers while he is gone...

Nucky Thompson and Owen Sleater visit Belfast, Ireland to offer the Irish Republican Army (IRA) the US Army’s surplus Thompson sub-machine guns. Nucky wants whiskey in exchange in order to gain funds for his own war. John McGarrigle turns down the proposal because of impending negotiations for peace with the English government. The other leaders of the IRA are less keen to end their struggle for independence and have McGarrigle assassinated allowing them to accept Nucky’s deal. Nucky is concerned that Sleater did not make him aware of this plot and then distressed by a telegram from Margaret Schroeder. Prosecutor Esther Randolph continues to build her case against Nucky, interviewing a subordinate in the Sheriff's Office...

Nucky Thompson makes a strong return to Atlantic City on the bootlegging front. He floods the city with the high quality, low cost whiskey but is deflated when he cannot get his trial moved back to town. He fires his attorney and arranges to visit New York to hire a new lawyer. Emily Schroeder waits for test results at the hospital and Margaret continues to blame her own sins for Emily’s illness. Teddy acts out, feeling neglected with Emily unwell and Nucky offers to take him to New York. In the city he is introduced to Bill Fallon by Arnold Rothstein and hires him as his defense attorney. After the meeting Teddy reveals that he saw Nucky burn down his father’s house. While Nucky is away Margaret donates her savings and jewellery to the Catholic church to prove her devotion. On his return they meet with Emily’s doctor and he tells them that her paralysis is likely to be permanent...

Jimmy Darmody takes refuge from his grief over the murder of his wife Angela in a drug and alcohol induced haze in a hotel in Princeton. Flashbacks to 1916 depict his time attending the college. His mother Gillian comes to visit him and he takes her to a social mixer where she meets Angela, then his girlfriend. Angela tells him that she is pregnant and he agrees to move in with her and offers a jokey proposal. He drinks heavily and when Gillian is manhandled by his teacher he beats the professor up. He then takes Gillian home and falls into bed with her; the mother and son commit incest. The next day Jimmy joins the army. While Jimmy is missing his bootlegging partners threaten Mickey Doyle into paying Jimmy out of his own profits. Doyle informs Prohibition AgentNelson Van Alden of their plans to meet and divide the profits, offering to split the whole take with Van Alden but Van Alden declines the offer. Jimmy eventually returns to Atlantic City where Gillian is coolly arranging a funeral and planning their future as a family. He flies into a rage when she tells him that his son Tommy will forget Angela in a month. He tries to strangle Gillian but is stopped by The Commodore, his father. After a struggle Jimmy kills The Commodore and falls unconscious due to his injuries. He wakes to find Richard Harrow cleaning up the scene and drifts back to sleep. He is woken again by Gillian who has brought Tommy down for reassurance. She tells him that she wants to forget what he did and promises that things will get better...

Jimmy Darmody attempts to make amends for his betrayal of Nucky Thompson, despite knowing that Nucky will never forgive him. He is aided by Richard Harrow. They end the African American workers strike by kidnapping the Ku Klux Klan members responsible for the raid on Chalky White’s warehouse and delivering them to Chalky along with compensation for the families of the men killed in the raid. Jimmy asks Chalky to arrange a meeting with Nucky. At the meeting he says that he wants to make things right, explains his reasons for the betrayal and asks what he can do to help Nucky. Nucky demands insight into the assassination attempt and Jimmy lays the blame on Eli Thompson. Nucky asks him to sabotage the legal case against him which includes charges of election rigging and the murder of Hans Schroeder. Jimmy settles The Commodore’s estate, destroying his will to ensure that he will inherit it. He is careful to check that it will pass to his son in the event of his death. Jimmy fails to convince his co-conspirators to implicate Eli instead of Nucky. He has Harrow murder Jim Neary on the eve of the trial. They force Neary to write a statement implicating Eli at gunpoint before staging his death as a suicide...